Firearm accessories, such as optical scopes, lights, night vision devices, and bipods, are typically attached to a firearm using a standardized mounting feature. One type of standardized mounting feature often integrated with a firearm, and to which an accessory may be attached, is commonly referred to as a “rail.” An accessory requiring power for operation (such as a light, a laser sight, a night vision device, etc.) typically includes a power source that is integrated with the accessory itself. The powered accessory, and its power source, are attached to the rail of the firearm prior to use.